This is a request for a competing renewal of an NIMH Midcareer Investigator Award in Patient-Oriented Research (NIMH staff has advised Dr. Katon that he could submit a competing renewal of his K-24 award as a full professor). This K-24 will build on Dr. Katon's prior research in: 1) developing innovative "collaborative care" interventions to improve the quality of care and outcomes of patients with depressive and anxiety disorders within primary care settings;2) improving understanding about the adverse impact of anxiety and depressive disorders in patients with common medical disorders;and 3) developing interventions to improve psychiatric outcomes in patients with chronic medical illness and comorbid depressive and anxiety disorders. The specific aims of this proposal include: 1) to continue to enhance Dr. Katon's epidemiologic, biostatistical and health economic skills in order to demonstrate in population-based studies the bidirectional adverse interactions between depression and chronic medical illness. The evidence from these population- based studies will be developed by a) showing in cross-sectional and longitudinal studies the adverse impact of depression on medical symptom burden, functional impairment, adherence to medical regimens, medical complications and mortality;and b) by demonstrating in longitudinal studies that residual depressive symptoms and incident complications of medical illness are associated with a higher risk of developing major depression and new deficits in functioning. Additional aims include: 2) to develop and test adaptations of collaborative care models in patients with depression and chronic medical illness that are targeted at improving medical disease control, behavioral risk factors, as well as improving quality of depression care;3) to continue to adapt collaborative care interventions and test their effectiveness in new populations experiencing disparities in quality of mental health care such as adolescent populations with depression, youth with attention-deficit hyperactivity disorder (ADHD) living in rural settings, and women with depression treated in Ob-Gyn settings;and 4) To continue to expand Dr. Katon's mentorship of junior investigators in mental health services research. These goals will be met through continued and expanded research activities, coursework in epidemiology, biostatistics and health economics and mentorship from external consultants. These courses, interactions with mentors, and mentored readings will improve Dr. Katon's ability as a mentor as well as enhancing the cutting edge research of his Health Services Division. RELEVANCE: The research that will be completed during the course of this award will increase knowledge about the importance of screening for and treating depression in patients with chronic medical illnesses;test new models of care in patients with depression and chronic medical illnesses aimed at improving quality of quality of depression and medical care;and adapt the collaborative care model to new populations (youth with ADHD and depression and women treated in Ob-Gyn settings) that experience disparities in quality of mental health care.